JPH0141610B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to the production of dialkylbenzene compounds using a modified crystalline zeolite catalyst to produce a mixture of products in which the 1,4-dialkylbenzene isomers are present in substantial excess over the normal equilibrium concentration. The disproportionation reaction of aromatic hydrocarbons in the presence of zeolite catalysts has been described by Grandio et al. in the Oil And Gas
Journal (Vol. 69, No. 48, 1971). U.S. Patent No. 3126422, No. 3413374, No.
Nos. 3,598,878, 3,598,879 and 3,607,961 disclose gas phase disproportionation reactions of toluene over various catalysts. In these conventional methods, the dimethylbenzene product is approximately 24% 1,4-isomer and approximately 54% 1,3-isomer.
%, and has an equilibrium composition of about 22% 1,2-isomer. Of the dimethylbenzene isomers, 1,3-dimethylbenzene is usually the least desired product, while 1,2- and 1,4-dimethylbenzene are the more useful products. Among them, especially 1 and 4
-Dimethylbenzene is important and useful in the production of terephthalic acid, an intermediate in the production of synthetic fibers such as "Dacron". Mixtures of dimethylbenzene isomers or mixtures of dimethylbenzene isomers and ethylbenzene have previously been separated by expensive ultra-rectification and multi-stage freezing steps.
Such methods are expensive to operate and have limited yields. A variety of modified zeolite catalysts have been developed for use in alkylating or disproportionating toluene with varying degrees of selectivity toward the 1,4-dimethylbenzene isomer. U.S. Patent No. 3972832, No. 4034053, No.
Nos. 4,128,592 and 4,137,195 disclose certain zeolite catalysts treated with phosphorus and/or magnesium compounds. Boron-containing zeolites are disclosed in US Pat. No. 4,067,920, and antimony-containing zeolites are disclosed in US Pat. No. 3,979,472. Similarly, U.S. Pat.
No. 4,117,026 discloses other modified zeolites useful in shape-selective reactions. Although the above-mentioned prior art is related to the subject matter of the present invention, a conversion method using a crystalline zeolite catalyst characterized by the specific treatment of the present invention has not been known until now, and no conversion method has been disclosed hitherto. I wasn't there. According to the present invention, a new method for converting aromatic compounds in the presence of a specific type of modified zeolite catalyst has been discovered. A particularly advantageous element of the invention is the selective production of 1,4-isomers of dialkylated benzene compounds. The process of the present invention uses an alkylated aromatic compound alone or in a mixture with a suitable alkylating agent such as methanol or ethylene to carry out the disproportionation or transalkylation of alkylbenzene compounds or the alkylation of aromatic compounds. It consists of selectively producing an excess of the 1,4-dialkylbenzene isomer over the normal equilibrium concentration by contacting it with a specific type of modified crystalline zeolite catalyst under conversion conditions. Certain types of crystalline zeolite catalysts of the present invention have a silica/alumina molar ratio of at least about 12, a control index of about 1 to 12, and have a control index of at least about 1 to 12, and can be prepared by pretreatment with a compound derived from elemental beryllium. It is modified by containing a small amount of oxide. In addition to treating the zeolite with a beryllium-containing compound, it may also be treated with a phosphorus-containing compound to precipitate a small amount of phosphorus oxide in addition to beryllium oxide. Embodiments of the present invention include alkylating aromatic compounds in the presence of the modified zeolite catalyst to obtain 1,4-
Dialkylbenzene isomers are 1,2- and 1,3
- Selective production in preference to isomers. A particularly preferred embodiment is the selective production of 1,4-dimethylbenzene from toluene and methanol and 1-ethyl-4-methylbenzene from toluene and ethylene. In another embodiment, alkylbenzene and polyalkylbenzene compounds are selectively disproportionated or transalkylated in the presence of said catalyst to produce 1,4-disubstituted benzenes in excess of normal equilibrium concentrations. . For example, under appropriate conditions of temperature and pressure, toluene in the presence of these catalysts produces dimethylbenzene and benzene enriched in the desired 1,4-isomer by a disproportionation reaction. The crystalline zeolites used herein are a new class of zeolite materials that exhibit unique properties. These zeolites have very low alumina content;
Although the silica/alumina molar ratio is therefore high, they are very active even when the silica/alumina molar ratio exceeds 30. Such a high activity is surprising considering that the activity of a catalyst generally depends on the aluminum atoms in the framework and/or the cations bonded to these aluminum atoms. These zeolites remain crystalline for long periods of time even in the presence of steam at such high temperatures that they irreversibly disintegrate the framework of other zeolites, such as type X and type A zeolites. Furthermore, if carbonaceous precipitates are formed, they can be removed by combustion at a higher temperature than normal to restore activity. These zeolites used as catalysts generally have low coke-forming activity and therefore can be used without regeneration for long periods of time with long intervals between regeneration steps by burning carbonaceous deposits with oxygen-containing gases such as air. . An important feature of the crystal structure of the new class of zeolites of the present invention is that the effective pores have an intermediate size between small pore Linde A and large pore Linde X, thereby allowing molecules into the intracrystalline free space. The pore windows of the crystal structure have a size defined by 10-membered rings of silicon atoms interconnected by oxygen atoms. Of course, it should be understood that these rings are formed by the regular arrangement of tetrahedra that form the anionic framework of the crystalline zeolite, and that the oxygen atom itself is located at the center of the tetrahedron. Bonded to silicon (or aluminum, etc.) atoms. The silica/alumina molar ratios described herein are determined by conventional analytical methods. This ratio represents as close as possible to the ratio in the hard anionic framework of the zeolite crystals, excluding aluminum in cationic or other forms in the binder or in the channels. Zeolites with a silica/alumina ratio of at least 12 are useful, but in some cases silica/alumina
Preference is given to using zeolites whose alumina ratio is substantially higher, for example 1600 or more. Additionally, in some cases, zeolites that are substantially aluminum-free, ie, have a silica/alumina molar ratio close to infinity, are useful and preferred. such as "high silica" or "highly siliceous"
Also included within the definition of this invention are zeolites. Also included within this definition are substantially pure silica analogs of the useful zeolites described herein, i.e., containing no measurable amounts of aluminum (infinite silica/alumina molar ratio).
There are also zeolites, which also impart the properties described herein in other respects. The new class of zeolites of the present invention exhibits "hydrophobic" properties with greater intracrystalline adsorption capacity for n-hexane than for water after activation. This hydrophobic property can be advantageous in some cases. The new class of zeolites useful in this invention have effective pore sizes that freely adsorb n-hexane. Furthermore, the crystal structure of the zeolites of the present invention must control the access of larger molecules. Whether such a property that controls the approach of molecules exists can be determined by knowing the crystal structure. For example, if the pore windows in the crystal are formed by eight-membered rings of silicon and aluminum atoms, access of molecules with a cross section larger than n-hexane is excluded, and such zeolites are of the desired type. isn't it. Although 10-membered rings are generally preferred, there are cases where the rings become too constricted or the pores become plugged, rendering them ineffective. Theoretically, a 12-membered ring does not provide sufficient control properties to achieve good conversion, but the constricted 12-membered ring structure of TMA offretite exhibits desirable control properties in some cases. It is undesirable to judge the usefulness of a particular zeolite solely from its theoretical structure, as there are other 12-membered rings that may be useful for some other reason. Rather than determining from the crystal structure whether a zeolite has the necessary properties to control the access of molecules of larger cross-section than n-paraffin, we prepared n-paraffin on a sample of zeolite at atmospheric pressure by following the procedure below.
The "control index" as defined herein is easily determined by continuously passing a mixture of equal weights of hexane and 3-methylpentane. First, a sample of zeolite in the form of pellets or extrudates is ground to approximately the size of coarse sand particles and placed in a glass tube. Before testing, the zeolite is treated with a stream of air at 540°C for at least 15 minutes. The zeolite is then flushed with helium and the temperature is adjusted to 290-510°C to give an overall conversion of 10-60%. The mixture of hydrocarbons is diluted with helium so that the molar ratio of helium/total hydrocarbon amount is 4/1, and the mixture is diluted with zeolite at a liquid hourly space velocity (i.e., unit volume of liquid hydrocarbon/unit volume of zeolite/unit time). Pass it on top. 20
After diversion, a sample of the effluent is taken and analyzed (most conveniently by gas chromatography) to determine the fraction remaining unchanged for each of the two hydrocarbons. Although the experimental procedure described above represents favorable conditions and allows the desired overall conversion of 10-60% for most zeolite samples, for very low activity samples, e.g. when the silica/alumina molar ratio is If the temperature is high, it may be necessary to use somewhat more severe conditions. In these cases, the temperature should be up to about 540° C. and the liquid hourly space velocity should be less than 1, such as less than 0.1, to achieve an overall conversion of at least about 10%. The "control index" is calculated as follows. Control index = log ₁₀ (remaining hexane) / log ₁₀ (remaining 3
- Methylpentane) The value of this control index is close to the ratio of the cracking rate constants of the two types of hydrocarbons. Zeolites suitable for the present invention are those having a control index of 1-12.
The control index values of some representative substances are shown below. Control index ZSM-4 0.5 ZSM-5 8.3 ZSM-11 8.7 ZSM-12 2 ZSM-23 9.1 ZSM-35 4.5 ZSM-38 2 ZSM-48 3.4 TMA offretite 3.7 Clinoptilolite 3.4 Beta 0.6 H-Zeolon (Mordenite) 0.4 REY 0.4 Amorphous Silica-Alumina 0.6 Erionite 38 The value of the control index is an important critical definition of the zeolite useful in this invention. However, it should be understood that according to the measurement method described above, the value of the control index will be somewhat different if measured under somewhat different conditions. The value of the control index will vary somewhat depending on the severity of the operating conditions (conversion conditions) and whether or not a binder is present. Similarly, factors such as zeolite crystal size and the presence of pore-clogging contaminants also influence the control index. Therefore, test conditions are selected such that more than one value for a particular zeolite falls within the control index range of 1 to 12. These zeolites control the access of molecules as described above and are considered to have a control index of 1-12. The novel class of highly siliceous zeolites defined herein, with a control index value of between 1 and 12, include those tested under two or more conditions within the range of temperature and conversion conditions mentioned above. If at least one value is in the range 1 to 12, then the value of the other control index is 1
For example, even if it is slightly smaller than
Even if it is 0.9 or even somewhat larger than 12, for example 14 or 15, those zeolites are considered to be usable in the present invention. Therefore, the control index values used herein are inclusive rather than exclusive. That is, a crystalline zeolite that has been tested under any combination of test conditions defined herein and determined to have a control index value of 1 to 12 will be tested under any combination of test conditions defined herein. Therefore, even if a control index value outside the range of 1 to 12 occurs when tested, that zeolite is considered to be a new class of zeolite that can be used in the present invention. Examples of the new class of zeolites defined here are ZSM-5, ZSM-11, ZSM-12, ZSM-
23, ZSM-35, ZSM-38, ZSM-48 and similar substances. ZSM-5 is US Patent No. 3702886 and Re29948
and the description of these patents,
In particular, the X-ray diffraction pattern of ZSM-5 is also cited here as a reference. ZSM-11 is disclosed in US Pat. No. 3,709,979, the description of which, in particular the X-ray diffraction pattern of ZSM-11, is also incorporated herein by reference. ZSM-12 is disclosed in US Pat. No. 3,832,449, the description of which, particularly the X-ray diffraction pattern, is also incorporated herein by reference. ZSM-23 is disclosed in US Pat. No. 4,076,842, the description of which, in particular the X-ray diffraction pattern, is also incorporated herein by reference. ZSM-35 is disclosed in US Pat. No. 4,016,245, the description of which, in particular the X-ray diffraction pattern, is also incorporated herein by reference. ZSM-38 is disclosed in US Pat. No. 4,046,859, the description of which, in particular the X-ray diffraction pattern, is also incorporated herein by reference. ZSM-48 is expressed as the following molar ratio of anhydrous oxide to 100 moles of silica. (0-15) RN: (0-1.5) M _2/o O: (0-2) Al ₂ O ₃ : (100) SiO ₂ In the above formula, M is at least one cation with a valence of n. RN is a _C1 - _C20 organic compound with at least one amine functionality with a pKa of 7. Part of the amine functionality may be protonated, especially when the composition has a tetrahedral aluminum framework. According to the conventional notation, the doubly protonated form is (RNH) ₂ O, which is stoichiometrically
Corresponds to 2RN+H ₂ O. The characteristic X-ray line pattern of synthetic zeolite ZSM-48 has the following substantial lines. d(A) Relative Intensity 11.9 Weak-Strong 10.2 Weak 7.2 Weak 5.9 Weak 4.2 Strongest 3.9 Strongest 3.6 Weak 2.85 Weak These values were determined using standard methods. The radiation was a copper K-alpha twin beam, and a self-recording scintillation counter spectrometer was used. The height of the peak I and its position as a function of double θ (θ = Bragg angle) were read from the spectrometer chart. From these, the relative intensity 100I/I _p (I _p is the intensity of the strongest line, that is, the peak) and the lattice spacing d in Å (observed value) corresponding to the recorded line were calculated. Even when sodium ions are ion-exchanged with other cations, the lattice spacing shifts slightly,
They exhibit essentially the same pattern with only slight changes in relative intensity. Other small changes may occur depending on the silicon/aluminum ratio of the sample and upon heat treatment. ZSM-48 can be made from a reaction mixture containing raw materials of silica, water, RN, alkali metal oxide (eg, sodium), and optionally alumina. The reaction mixture has a composition, expressed in molar ratios of oxides, in the following ranges: Reactant wide range preferred range Al ₂ O ₃ /SiO ₂ = 0 to 0.02 0 to 0.01 Na/SiO ₂ = 0 to 2 01 to 1.0 RN/SiO ₂ = 0.01 to 20 0.05 to 1.0 OH ^- /SiO ₂ = 0 to 0.25 0 ~ 0.1 H ₂ /SiO ₂ = 10 ~ 100 20 ~ 70 H ⁺ (added) / SiO ₂ = 0 ~ 0.2 0 ~ 0.05 where RN has an amine functional group with pKa 7
It is a _C1 - _C20 organic compound. This mixture is kept at 80-250°C until crystals form. H ⁺ (added) is the number of moles of acid added in excess of the number of moles of hydroxide added. H ⁺ (added) and OH
When calculating the value of , the acid (H ⁺ ) is assumed to contain both hydronium ion and aluminum, whether free or coordinated. Thus, for example, aluminum sulfate is considered to be a mixture of aluminum oxide, sulfuric acid and water. Amine hydrochloride is a mixture of amine and HCl. When producing highly siliceous form of ZSM-48, no alumina is added. Therefore, the only alumina present is that which occurs as an impurity in the reactants. Preferably, crystallization is carried out at 80-250°C in an autoclave or static bomb reactor under pressure. Thereafter, the crystals are separated from the mother liquor and removed. The composition is manufactured using materials that provide suitable oxides. Such materials include sodium silicates, silica hydrosols, silica gels, silicic acid, RN, sodium hydroxide, sodium chloride, aluminum sulfate, sodium aluminate, aluminum oxide or aluminum itself. RN is a C1 _{- C20} organic compound having at least one amine functionality with a pKa of 7 as described above, such as _C3 - _C18 primary, secondary and tertiary amines,
Cyclic amines (e.g. piperidine, pyrrolidine and piperazine) and polyamines, e.g. _NH2
-C _o H _2o -NH ₂ (n=4 to 12), etc. The initially present cations are then at least partially replaced by subsequent calcination and/or ion exchange with other cations. That is, the initially present cations are exchanged with hydrogen or hydrogen ion precursors, or
exchanged for metals of the same group. It is therefore conceivable, for example, to exchange the cations present from the beginning with ammonium or hydronium ions. These catalytically active forms include, inter alia, hydrogen, rare earth metals, aluminum, manganese and other metals of groups 1 to 1 of the periodic table. By reference to the aforementioned patents which disclose in detail examples of a novel class of zeolites that can be used in the present invention, these crystalline zeolites have been identified by their respective X-ray diffraction patterns. Ru. As previously stated, the present invention also contemplates the use of catalysts with substantially unlimited silica/alumina molar ratios. Therefore, even though the aforementioned patents are cited, the zeolites used in the present invention are not limited to those having the specific silica/alumina molar ratios described in these cited documents. Those having the same crystal structure as described in these documents but substantially free of alumina are also useful in the present invention and may be preferred. The crystal structure is identified by an X-ray diffraction pattern (like a fingerprint), and the identification of a particular crystalline zeolite material is thereby made. When the aforementioned zeolites are prepared in the presence of organic cations, they become substantially catalytically inactive. This is probably because the intracrystalline free space is occupied by organic cations in the preparation solution. However, these can be used in an inert atmosphere for example 540
℃ for 1 hour, then with ammonium salt,
Activation can be achieved by base exchange and subsequent calcination at 540° C. in air. Although the presence of organic cations in the production solution is not a necessary condition for the production of this type of zeolite, the presence of these cations favors the production of this type of special zeolite. It seems so. It is generally desirable to activate this type of catalyst by base exchange with an ammonium salt and then calcination in air at about 540° C. for about 15 minutes to about 24 hours. Natural zeolites can be converted to zeolite structures of the type identified herein by various activation procedures, other treatments such as base exchange, steaming, alumina extraction, and calcination, alone or in combination.
Examples of natural minerals that can be treated in this way are ferrierite, brieusterite, stilbite, dachialdite, epistilbite, hollandite, and clinobutyrolite. Examples of preferred crystalline zeolites used here include ZSM-5, ZSM-11, ZSM-12,
Among them, ZSM-23, ZSM-35, ZSM-38 and ZSM-48 are particularly preferred. In a preferred embodiment of the invention, these zeolites are selected, especially those having a crystalline framework density in the dry hydrogen form of about 1.6 g/cm ³ or more. It has been discovered that zeolites that meet all three conditions listed above are the most desirable for several reasons. When producing hydrocarbon products or by-products catalytically, such zeolites tend to maximize production of hydrocarbon products in the gasoline boiling range. That is, preferred zeolites useful in the present invention have a control index value of about 1 to 12, a silica/alumina molar ratio of at least about 12, and a dry crystal density of about 1.6 g/cm ³ or more. be. For known structures, the dry density can be calculated from the total number of silicon and aluminum atoms per 1000 cubic Angstroms. This method of calculation is described on page 19 of the article entitled "Zeolite Structure" by W. M. Meier, which is also cited here by reference, and the Society
Proceedings of the Chemical Industry (London, 1968).
Conference on Molecular Sieves” (London,
April, 1967). If the crystal structure is not known, crystalline framework density can be determined by conventional pycnometer methods. For example, it can be measured by immersing a dry hydrogen form of zeolite in an organic solvent that is not adsorbed by its crystals. Alternatively, crystal density may be measured by using mercury, which fills the intercrystal voids but does not penetrate intracrystalline free space. The unique activity and stability of this particular class of zeolites is due to their crystalline anionic framework density of approximately 1.6 g/
It is associated with being high (cm ³ or more). This high density is necessarily associated with a relatively small amount of free space within the crystal, which results in a more stable structure. However, this free space is important as a site for catalytic activity. The crystalline framework densities of some representative zeolites are shown below, some of which are not within the scope of the present invention. Void volume Frame density Ferrierite 0.28cc/cc 1.76g/cc Mordenite .28 1.7 ZSM-2,-11 .29 1.79 ZSM-12 - 1.8 ZSM-23 - 2.0 Datialdite .32 1.72 L .32 1.61 Clinoptilolite .34 1.71 Laumontite .34 1.77 ZSM-4 (Omega) .38 1.65 Wheelandite .39 1.69 P .41 1.57 Offretite .40 1.55 Levinite .40 1.54 Erionite .35 1.51 Gmelinite .44 1.46 Chabasite .47 1.45 A. 5 1.3 Y .48 1.27 When synthesized in the alkali metal form, zeolites are generally produced in the intermediate ammonium form by ammonium ion exchange, and the ammonium form is converted to the hydrogen form by calcination to conveniently produce the hydrogen form. can do. In addition to the hydrogen form, other forms of zeolite with a reduction of less than about 1.5% by weight of originally present alkali metals may also be used. That is, the alkali metal originally present in the zeolite can be replaced with other suitable metal cations from Groups ~ of the Periodic Table, such as nickel,
Ion exchange may also be performed with copper, zinc, palladium, calcium or rare earth metals. When carrying out particularly desirable chemical conversion steps,
Preferably, the crystalline zeolite is used in a matrix of other materials that are resistant to the temperatures and other conditions used in the conversion process. These host materials are useful as binders and provide the catalyst with durability to withstand the harsh temperature, pressure, and reactant feed rate conditions of many cracking processes. Examples of useful host materials include synthetic and natural materials as well as inorganic materials such as clays, silica, and/or metal oxides. The latter may be natural or in the form of a gel or gelatinous precipitate, such as a mixture of silica and metal oxides. Examples of natural clays that can be composited with zeolites include montmorillonite and kaolins, which include subbentonite and kaolin, commonly known as Dixie, McNamee-Georgia, and Florida clays, whose main minerals are Ingredients are halloysite, kaolinite, dateskite,
It is nacrite or anorchisite. These clays may be used in their raw, as-mined state, or may be used after first being calcined, acid treated, or chemically modified. In addition to the above substances, the zeolites used in the present invention include alumina,
Silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryria, and silica-titania and the ternary systems silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia, and silica- It may also be composited with a porous matrix material such as magnesia-zirconia. These matrices may be in the form of a co-gel. The relative proportions of the zeolite component and the inorganic oxide gel matrix vary widely, with the zeolite content in the anhydrous state representing about 1 to 99% by weight of the dry composite, usually about 5 to 80% by weight. According to the invention, the crystalline zeolite is contacted with a solution of one or more compounds of the element beryllium (Be). Solutions of such compounds are prepared using solvents that are inert to the metal-containing compound and the zeolite. Some examples of these suitable solvents include water, aromatic and aliphatic hydrocarbons, alcohols, organic acids (such as formic acid, acetic acid, propionic acid, etc.) and inorganic acids (such as hydrochloric acid, nitric acid, and sulfuric acid). . Other commonly available solvents such as halogenated hydrocarbons, ketones, ethers, etc. are also useful for dissolving metal compounds or complexes.
Generally the most useful solvent is water. However, the choice of solvent for a particular compound will of course be determined by the properties of that compound and should not be considered as absolutely suitable for all of the above. . Examples of typical beryllium-containing compounds include beryllium acetate, beryllium butyrate, beryllium carbonate, beryllium chloride, beryllium bromide, beryllium iodide, beryllium fluoride, beryllium oxide,
These include beryllium hydride, beryllium nitrate, beryllium sulfate, beryllium sulfide, beryllium propionate, beryllium oxalate, beryllium nitride, beryllium acetylacetonate, and beryllium benzenesulfonate. It should be understood that the above list is only a partial list of representative metal compounds useful in the practice of the present invention and is not an exhaustive list of beryllium-containing compounds that may be used. Those skilled in the art will readily recognize that there are many other known beryllium salts or complexes that are useful in providing beryllium-containing solutions suitable for combination with zeolites in the manner described below. You will understand. The reaction between the zeolite and the beryllium treatment agent is carried out by bringing the zeolite into contact with the beryllium treatment agent. If the beryllium treatment agent is a liquid, the beryllium treatment agent is used as a solution in a solvent when contacting the zeolite. Any solvent that is relatively inert to the beryllium treatment agent may be used. Examples of suitable solvents are water and aliphatic, aromatic or alcoholic liquids.
The processing agent may be used as a liquid without a solvent. If the treatment agent is in a gas phase, it may be used as is, but it may be used in combination with a gaseous diluent that is relatively inert to the treatment agent and the zeolite, such as helium or nitrogen or an organic solvent such as octane or toluene. It may also be used as a mixture. It is also preferred to heat the catalyst impregnated with the beryllium compound after manufacture and before use. This heating can be carried out in the presence of oxygen, for example air. Heating can be carried out at temperatures of about 150°C, but elevated temperatures up to about 500°C are preferred. Heating is generally carried out for 1 to 5 hours, but may be extended for 24 hours or more. Heating temperatures above about 500° C. can be used, but are generally not necessary. At temperatures of about 1000°C, the crystal structure of zeolite tends to deteriorate. After heating at high temperatures in air, beryllium is believed to actually exist in an upstream form, for example as BeO. The amount of beryllium oxide incorporated into the zeolite should be at least about 0.25% by weight. However, the amount may be at least about 0.5%, especially when combined with a binder, such as 35% by weight alumina.
Preferably, it is % by weight. Depending on the amount and type of binder present, the amount of beryllium oxide is approximately 25
It may be more than % by weight. Preferably the amount of beryllium oxide added to the zeolite is from about 0.5 to about 20% by weight.
It is. The amount of beryllium incorporated into the zeolite by reaction with elemental beryllium or beryllium-containing compounds depends on several factors. One of these factors is the reaction time, ie the time the zeolite and beryllium-containing source are kept in contact with each other. All other factors being equal, the longer the reaction time, the greater the amount of metal incorporated into the zeolite. Other factors that influence the amount of beryllium incorporated into the zeolite include the reaction temperature, the concentration of the treatment agent in the reaction mixture, the degree of dryness of the zeolite before reacting with the metal-containing compound, and the zeolite after it has reacted with the treatment agent. drying conditions, and the amount and type of binder mixed into the zeolite. In yet another embodiment of the invention, the metal oxide-zeolite complex is further modified with phosphorus so that from about 0.25 to about ₃₀ % by weight phosphorus sulfide (calculated as _P2O5 ) is combined with the zeolite. . The preferred amount of phosphorous oxide is about 1 to 1 of the weight of the treated zeolite.
It is 25% by weight. The phosphorus treatment of the zeolite is preferably carried out before the modification treatment with beryllium as described above. The reaction of the zeolite with the phosphorus-containing compound is carried out essentially as described for the beryllium-containing compound above, and the total amount of oxides combined with the zeolite, i.e. the total amount of phosphorus oxide and beryllium oxide, is It is about 2 to 35% by weight of the weight of . Typical examples of phosphorus-containing compounds used include PX ₃ , RPX ₂ , R ₂ PX, R ₃ P, X ₃ PO,
(XO) ₃ PO, (XO) ₃ P, R ₃ P=O, R ₃ P=S,
RPO ₂ , PRS ₂ RP (O) (OX) ₂ , RP (S) (SX) ₂ ,
R ₂ P (O) OX, R ₂ P (S) SX, RP (SX) ₂ , ROP
(OX) ₂ , RSP(SX) ₂ , (RS) ₂ RSP(SR) ₂ , and (RO) ₂ POP(OR) ₂ (wherein R is alkyl or aryl, such as phenyl group, and X is hydrogen , R or a halide). Examples of these compounds include the first RPH ₂ ,
2nd R ₂ PH and 3rd R ₃ P, phosphin, such as butyl phosphin; tertiary phosphin oxide
R ₃ PO, e.g. tributylphosphine oxide, tertiary phosphine sulfide, R ₃ PS, primary RP
(O)(OX) ₂ , and the second R ₂ P(O)OX, phosphonic acids, such as benzenephosphonic acid; its corresponding sulfur derivatives, such as RP(S)(SX) ₂ and
R ₂ P(S)SX, esters of phosphonic acids, such as dialkyl phosphonates, (RO) ₂ P(O)
H, dialkyl alkyl phosphonate,
(RO) ₂ P(O)R, and alkyl dialkyl phosphonates, (RO)P(O)R ₂ ; phosphinous acid, R ₂ POX, such as diethyl phosphinite, primary (RO)P(OX) ₂ , second (RO) ₂ POX and third (RO) ₃ P, phosphites and their esters, such as monopropyl esters, alkyl dialkyl phosphinites, (RO)PR ₂ and dialkyl alkyl phosphinites, (RO) ₂ There is PR ester. Its corresponding sulfur derivatives are (RS) ₂ P(S)H, (RS) ₂ P(S)R, (RS)P(S)
R ₂ , R ₂ PSX, (RS) P(SX) ₂ , (RS) ₂ PSX,
(RS) ₃ P, (RS) PR ₂ and (RS) ₂ PR may also be used. Examples of phosphite esters are trimethyl phosphite, triethyl phosphite, diisopropyl phosphite, butyl phosphite and pyrophosphite, such as tetraethyl pyrophosphite. The alkyl group in said compound contains 1 to 4 carbon atoms. Examples of other suitable phosphorus-containing compounds include phosphorus halides such as phosphorus trichloride, phosphorus tribromide and phosphorus triiodide, alkyl phosphorus fluorodichloridites, (RO)PCl ₂ , dialkyl phosphorus fluorochloridites, ( RO) ₂ PCl, dialkyl phosphinochloridite, R ₂ PCl, alkyl alkyl phosphinochloridite, (RO)(R)P(O)Cl,
Dialkylfuosphinochloridate, _R2P (O)
There are Cl and RP(O) _Cl2 . Examples of its corresponding sulfur derivatives that may be used include (RS)PCl ₂ ,
(RS) ₂ PCl, (RS) (R) P(S) Cl and R ₂ P(S)
There is Cl. Examples of preferred phosphorus-containing compounds include diphenylphosphine chloride, trimethylphosphite, phosphorus trichloride, phosphoric acid, phenylphosphine oxychloride, trimethylphosphate, diphenylphosphinous acid, diphenylphosphinite, diethyl chloro. Thiophosphate, acidic methyl phosphate, and other alcohols
There is _{a P2O5} reaction product. Particularly preferred are ammonium phosphates, such as diammonium monohydrogen phosphate,
(NH ₄ ) ₂ HPO ₄ and monoammonium dihydrogen phosphate,
NH ₄ , H ₂ PO ₄ . As another modification treatment, zeolite is
Steam treatment involves contact with an atmosphere containing about 5 to about 100% water vapor at about 250 to about 1000° C. and under pressures from below atmospheric pressure to several hundred atmospheres for about 15 minutes to about 100 hours. Steaming is preferably performed at a temperature of about 400 to about 700°C for about 1
~Conducts approximately 24 hours. Another modification process involves precoking the catalyst to deposit a coating of about 2 to about 75 weight percent coke, preferably about 15 to about 75 weight percent. Precoking involves contacting the catalyst with a hydrocarbon such as toluene under very harsh conditions, or by using a hydrogen/hydrocarbon molar ratio as low as 0 to 1 for a period of time sufficient to precipitate the desired amount of coke. This is done by making contact. The crystalline zeolite catalyst may be suitably modified by a combination of steaming and pre-coking of the catalyst under the above conditions. Alkylation of aromatic compounds in the presence of the catalyst is carried out by contacting the aromatic with an alkylating agent. A particularly preferred embodiment is the alkylation of toluene, where the alkylating agent used is methanol or other known methylating agents or ethylene. This reaction is carried out at a temperature of about 250 to about 750°C, preferably about 300 to 650°C. At high temperatures, zeolites with high silica/alumina ratios are preferred. For example, if the SiO ₂ /Al ₂ O ₃ ratio is 300 or more,
ZSM-5 is extremely stable even at high temperatures. This reaction is generally carried out at atmospheric pressure, but at approximately 10 ⁵ to 10 ⁷ N/
Pressures within the range of ¹ to 100 atmospheres may be used. Examples of suitable alkylating agents include ethylene,
These include olefins such as propylene, butene, decene and dodecene, as well as formaldehyde, alkyl halides and alcohols, the alkyl portion of which has 1 to 16 carbon atoms. Many other aliphatic compounds having at least one reactive alkyl group can be used as alkylating agents. Examples of aromatic compounds that are selectively alkylated in the present invention include aromatic hydrocarbons such as benzene, ethylbenzene, toluene, dimethylbenzene, diethylbenzene, methylethylbenzene, propylbenzene, isopropylbenzene, isopropylmethylbenzene, or Any mono- or di-substituted benzene that can be alkylated is included. The alkylating agent/aromatic compound molar ratio is generally from about 0.05 to about 5. For example, when methanol is used as the methylating agent and the aromatic compound is toluene, a suitable methanol/toluene molar ratio has been found to be about 1 to 0.1. The reaction is suitably conducted utilizing a feed weight hourly space velocity (WHSV) of from about 1 to about 1000, preferably from about 1 to about 200. 1,4-dimethylbenzene, 1-ethyl-
Reaction products consisting primarily of 1,4-dialkyl isomers such as 4-methylbenzene or 1, containing relatively small amounts of 1,3-dialkyl benzene isomers
The mixture of 4- and 1,2-isomers may be separated by any suitable means. One example of these means is, for example, passing the reaction product stream through a water condenser and then passing the organic phase through a column where chromatographic separation of the aromatic isomers takes place. When transalkylation is carried out, the transalkylating agent is an alkyl or polyalkyl aromatic hydrogen whose alkyl group has from 1 to about 5 carbon atoms, such as toluene, xylene, trimethylbenzene, triethylbenzene, dimethylethylbenzene. , ethylbenzene, diethylbenzene, ethyltoluene, etc. Another embodiment of the invention is a selective disproportionation reaction of alkylated aromatic compounds to produce dialkylbenzenes, in which the 1,4-dialkyl isomer is produced in excess of the normal equilibrium concentration. In such cases, it should be understood that the disproportionation reaction is a special case of the transalkylation reaction in which the alkylatable hydrocarbon and the transalkylating agent are the same compound. For example, toluene acts as a donor and acceptor for migrating methyl groups, producing benzene and xylene. The transalkylation and disproportionation reactions are carried out by mixing the reactants with the modified zeolite catalyst at temperatures of about 250 to 750°C at atmospheric pressure (10 ⁵ N/m ² ) and about 100 atm (10 ⁷ N/m ² ).
This is done by contacting with pressure between. The WHSV of the reactant is usually about 0.1 to about 50.
Preferred alkyl aromatics suitable for use in the disproportionation reaction include toluene, ethylbenzene, propylbenzene, and virtually any monosubstituted alkylbenzene. These aromatic compounds are 1,4-dimethylbenzene and 1,4-dimethylbenzene, respectively.
- diethylbenzene, 1,4-dipropylbenzene or other 1,4-dialkylbenzenes, etc., with benzene being the major by-product in each case. This product is recovered from the reactor effluent by conventional means such as distillation;
The desired products, benzene and dialkylbenzene, are collected and the unreacted aromatic components are recycled for further reactions. The hydrocarbon conversion process of the present invention is carried out as a batch, semi-continuous or continuous operation using fixed bed or moving bed catalyst systems. The used catalyst in the moving bed reactor is directed to a regeneration zone where the coke is incinerated from the catalyst at high temperature in an oxygen-containing atmosphere such as air, and the regenerated catalyst is then transferred to a conversion zone for further contact with the feedstock. It is circulated. Regeneration takes place in a conventional manner in a fixed bed reactor, where the coke is incinerated using an inert gas containing a small amount of oxygen (0.5-2%) to maintain the temperature at a maximum of about 500-550°C. . The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited thereto, and those skilled in the art will appreciate that various modifications can be made based on these descriptions. You should understand. In the following examples, Example 1A, Example 1B, Example 2, Example 4A, Example
4B, Example 5 is a comparative example, Example 3 is a comparative production example, Example 6 is a production example, and the others are examples. Example 1A Alkylation reaction with unmodified zeolite ZSM-5 5 g of ZSM-5 (silica/alumina molar ratio =
70; 65% on alumina binder) were placed in a quartz flow reactor and heated to various temperatures from 350 to 500°C.
A 4/1 molar ratio toluene/methanol mixture was passed through the zeolite catalyst at a weight hourly space velocity (WHSV) of 10. measuring the reactor effluent;
The results obtained at various temperatures are shown below.

[Table] Example 1B In a similar manner, each
Toluene was alkylated with ethylene by passing toluene and ethylene at WHSV of 7.0 and 0.5. Results at various temperatures are shown below.

[Table] Example 2 Disproportionation reaction using unmodified zeolite ZSM-5 Toluene was converted into HZSM-5 (SiO ₂ /Al ₂ O ₃ molar ratio =
70; 65% on alumina binder) at a WHSV of 3.5-3.6 at a temperature of 450-600°C. The results obtained are shown in the table below.

[Table] Example 3 Production of phosphorus-modified zeolite Ammonium ZSM-5 (65 on alumina binder)
%) was added to a solution of 80 g of diammonium monohydrogen phosphate in 300 ml H ₂ O at approximately 90°C. After being left at about 90°C for 2 hours, the zeolite was filtered, dried at 90°C for 2 hours, and then calcined at 500°C for an additional 2 hours. The recovered P-ZSM-5 zeolite contained 3.43% by weight phosphorus. Example 4A Alkylation reaction using phosphorus-modified zeolite Toluene/methanol feed stream (molar ratio = 4/
1) was passed over 5.0 g of the P-ZSM-5 zeolite of Example 3 for alkylation of toluene with methanol. The feedstock WHSV was 10, and the reactor temperature was varied from 400°C to 600°C. The results obtained are summarized below.

[Table] Example 4B In a similar manner, using toluene (WHSV = 7.0) and ethylene (WHSV = 0.5) feed streams.
Ethylation of toluene was carried out in the presence of P-ZSM-5 catalyst at 400°C. Toluene conversion rate is 74.8%
So, the selectivity of ethyltoluene to the para-isomer is
It was 55.5%. Example 5 Disproportionation reaction with phosphorus-modified zeolite Disproportionation reaction of toluene by passing a stream of toluene over the P-ZSM-5 catalyst of Example 3 at a temperature of 475-550°C with a WHSV of 3.5 in the feedstock. was tested. The results obtained are summarized in the table below.

[Table] Example 6 Production of Be-P-modified zeolite P-modified ZSM-5 zeolite produced in Example 3
6.0 g was added to a solution of 5.0 g of beryllium acetate in 15 ml of water at 90°C. This mixture was heated to 80-90℃ for 2 hours.
The zeolite was collected and dried at 90° C. for 1.2 hours. This zeolite was then calcined at 500℃ for 2.5 hours to produce Be-P-ZSM-5 with a beryllium content (calculated value) of 1.2%.
Obtained 6.2g. Example 7 Alkylation reaction using Be-P-modified zeolite Toluene/methanol mixture (molar ratio = 4/
1) and 5.0 g of Be-P-ZSM-5 zeolite from Example 6.
Alkylation of toluene with methanol was carried out by passing it over the top. Keep the reactor at 400℃,
The WHSV of the raw material was set to 10. As a result, the conversion rate of toluene was 38.8%, and the P in the xylene product was
- The selectivity of isomers was 79.2%. Zeolite modified with beryllium compounds is unmodified ZSM-5 or P-modified ZSM.
-5.The selectivity of the para-isomer was substantially higher than with either of the methods. Example 7B Ethyltoluene was prepared by reacting ethylene and toluene in the presence of the Be-P-ZSM-5 zeolite of Example 6. This reaction takes place at 400℃
The reactant feed rate (WHSV) was 7.0 for toluene and 0.5 for ethylene. The conversion rate of toluene was 76.9%, and the selectivity of ethyltoluene to the para isomer was 81.4%. Again, zeolites treated with beryllium-containing compounds had substantially increased selectivity for the para isomer over either unmodified or P-modified zeolites. Example 8 Disproportionation reaction with Be-P-modified zeolite Example 6 Toluene feed stream at 500℃ with WHSV of 3.5
The disproportionation reaction of toluene was carried out by passing it over a sample of Be-P-ZSM-5 zeolite. The conversion of toluene was 10.5% and the yield of para isomer in the xylene product was 52.5%. The level of selectivity for the para isomer obtained by utilizing beryllium-modified zeolite catalysts is that of unmodified ZSM-5 (Example 2) or P-ZSM-5 (Example 5).
This was unexpectedly better than either of the methods, clearly demonstrating the effect of the beryllium modification treatment of zeolite.

Claims (1)

[Claims] 1. An aromatic compound is mixed with an alkylating agent at a temperature of 250 to 750°C and a pressure of 1 atm to 100 atm (10 ⁵ to ^{10 7} N/m ² ), with a silica/alumina molar ratio of at least 12. 1,4 by contacting in the presence of a zeolite catalyst having a control index of 1 to 12 and previously modified by treatment with one or more beryllium compounds to precipitate at least 0.25% by weight of beryllium oxide. - A process for the alkylation of aromatic compounds, which consists in producing dialkylbenzene compounds in which the dialkylbenzene isomers are present in excess of the normal equilibrium concentration. 2 Claim 1 in which the temperature is 300 to 650°C
The method described in section. 3 The amount of beryllium oxide in the modified zeolite catalyst
The method according to claim 1, wherein the amount is 0.5 to 20% by weight. 4. A zeolite according to any one of claims 1 to 3, which is further modified by treating it with a phosphorus compound to precipitate at least 0.25% by weight of phosphorus oxide. the method of. 5. Any one of claims 1 to 4, in which zeolite is mixed with a binder.
The method described in section. 6 Claims 1 to 5, wherein the alkylation is a transalkylation reaction of an aromatic compound that produces a dialkylbenzene compound in which the 1,4-dialkylbenzene isomer is present in excess of the normal equilibrium concentration. The method described in any one of the above. 7. Claim 1, wherein the alkylation is a disproportionation reaction of alkylbenzenes to produce dialkylbenzenes and benzenes in which the 1,4-dialkylbenzene isomer is present in excess of the normal equilibrium concentration.
The method described in any one of paragraphs to paragraphs 5 to 5. 8 Zeolite is ZSM-5, ZSM-11, ZSM-
12, ZSM―23, ZSM―35, ZSM38 or ZSM―
48. The method according to any one of claims 1 to 7.